Numerous epidemiologic and angiographic studies have analyzed the association of serum cholesterol and triglyceride and hyperlipoproteinemia with coronary arterial disease. Little morphologic information, however, is available on the status of the coronary arteries in patients with hyperlipoproteinemia. In this report, previous studies are reviewed and results of study of the coronary arteries in 43 necropsy patients with types II, III or IV hyperlipoproteinemia or normal lipoprotein patterns are presented.